1. Field of the Invention
The invention relates generally to steering column assemblies, and more particularly to telescoping and tilting steering column assemblies.
2. Related Art
It is often convenient to a driver of a vehicle to have a steering column assembly having a hand wheel that can both telescope inwardly and outwardly, while also being able to tilt upwardly and downwardly. The tilting and telescoping features of a steering column assembly allow the driver to adjust the hand wheel to the desired position while driving the vehicle, while also allowing the driver to position the hand wheel to a position that best allows getting in and out of the vehicle. Generally, when driving a vehicle, the desired xe2x80x9cusexe2x80x9d position of the hand wheel is in a telescopically extended position toward the driver, while also having a certain degree of tilt to provide the most comfortable position of the hand wheel. However, when the driver is entering or exiting the vehicle, generally, the most desired xe2x80x9cstowedxe2x80x9d position of the hand wheel is fully retracted and tilted in an upward position to provide optimum access.
One problem encountered by such systems is that the hand wheel, when moved to a telescopically retracted and upwardly tilted stowed position, may interfere with the instrument panel which is undesirable and can cause potential damage to the instrument panel, and/or hand wheel.
One solution for preventing the hand wheel from contacting the instrument panel when in the fully retracted upwardly tilted stowed position is to limit the freedom of tilting movement and/or telescoping movement so that the hand wheel does not move far enough to contact the instrument panel of the hand wheel. However, this solution has the inherent drawback of limiting the overall telescoping and tilting adjustability when the hand wheel is in the extended use position, and thus offering less than optimum adjustability to the driver.
A position dependent tilt and telescoping steering column constructed according to the present invention overcomes or greatly minimizes the above limitations of prior steering columns.
A steering column assembly is constructed to allow for an otherwise full range of tilting while preventing the steering column assembly from interfering with any portion of the vehicle while in a tilted position. The steering column assembly has an upper steering shaft that is capable of telescoping to an extended and retracted position, while also being capable of tilting from an untilted position to a tilted position. While the steering column assembly is in the extended position, the upper steering shaft can be tilted to a position, thus forming a first maximum tilt angle between the untilted position and the tilted position In addition, while the steering column assembly is in the retracted position, the upper steering shaft is moveable to a tilted position to form a second maximum tilt angle between the untilted position and the tilted position. The second maximum tilt angle formed while in the retracted position is less than the first maximum tilt angle formed while in the extended position, thus preventing the steering column assembly from interfering with any portion of a vehicle.
One advantage offered by this invention is that the steering column assembly, while in an extended position, has a full range of tiltable movement, however while in a retracted position has a reduced degree of tiltable movement to prevent interfering of a hand wheel with an instrument panel or any other portion of the vehicle.
Another advantage offered by this invention is that the degree of tilt of the upper steering shaft throughout the range of telescopic travel can be provided to best suit the intended application.